Clean Water Act discharge permit · NPDES IL0072931
CHESTER STP, Chester, IL: NPDES IL0072931 discharge permit, effluent exceedances, inspections, penalties
- Administratively continuedPermit status
- MajorDischarger class
- 31Pollutants under a numeric limit
- 6Pollutants with an effluent exceedance
CHESTER STP, held by CITY OF CHESTER, holds NPDES permit IL0072931, which discharges to Mississippi River. EPA’s file records it issued September 29, 2011 and expiring October 31, 2016. The status and dates are as EPA’s permit file stood when Velarion loaded it (September 14, 2026); EPA’s free Detailed Facility Report on ECHO carries the permit’s current standing.
Identity
| Facility as filed | CHESTER STP |
|---|---|
| Permittee as filed | CITY OF CHESTER |
| NPDES ID | IL0072931 |
| Permit status | Administratively continued (past its expiration date and still in force until reissued) |
| Permit type | Individual permit |
| Discharger class | Major discharger |
| Facility type | Publicly owned treatment works |
| Program | Publicly owned treatment works |
| Issued | September 29, 2011 |
| Expiration date | October 31, 2016 |
| Address | Chester, IL 62233 |
| Receiving water | MISSISSIPPI RIVER |
| Receiving water impaired | 303(D) Listed |
| Subwatershed | Old River-Mississippi River (HUC 071401050114) |
Cited to the EPA ICIS-NPDES permit file (ECHO download).
Effluent limits and exceedances
- 52Pollutants on file
- 31Under a numeric limit
- 34With a violation of any kind
- 6With an effluent exceedance
An effluent exceedance is a discharge monitoring report value over the permit’s numeric limit (EPA’s violation code E90). A violation of any kind also counts a report not filed. Each row is EPA’s own count for that pollutant.
| Pollutant or measure | Limits | Violations, any kind | Effluent exceedances | Latest exceedance | Largest exceedance, as filed |
|---|---|---|---|---|---|
| Coliform, fecal general | 1 | 3 | 3 | October 31, 2025 | 163% over the limit |
| Solids, total suspended | 5 | 7 | 2 | March 31, 2001 | 53% over the limit |
| Nitrogen, ammonia total [as N] | 6 | 2 | 2 | January 31, 2024 | 344% over the limit |
| Arsenic, dry weight | 3 | 2 | 2 | December 31, 2009 | 924% over the limit |
| Oxygen, dissolved [DO] | 5 | 2 | 1 | July 31, 2021 | 1% over the limit |
| Lead, sludge, total, dry weight [as Pb] | 3 | 1 | 1 | June 30, 2009 | 2% over the limit |
| Flow, in conduit or thru treatment plant | 4 | 4 | 0 | ||
| BOD, carbonaceous [5 day, 20 C] | 4 | 4 | 0 | ||
| pH | 2 | 4 | 0 | ||
| Mercury, total [as Hg] | 0 | 3 | 0 | ||
| Nitrogen, total [as N] | 1 | 2 | 0 | ||
| Oil & Grease | 0 | 2 | 0 | ||
| Cyanide, total [as CN] | 0 | 2 | 0 | ||
| Fluoride, total [as F] | 0 | 2 | 0 | ||
| Arsenic, total [as As] | 0 | 2 | 0 | ||
| Barium, total [as Ba] | 0 | 2 | 0 | ||
| Cadmium, total [as Cd] | 0 | 2 | 0 | ||
| Chromium, hexavalent [as Cr] | 0 | 2 | 0 | ||
| Chromium, total [as Cr] | 0 | 2 | 0 | ||
| Copper, total [as Cu] | 0 | 2 | 0 | ||
| Iron, total [as Fe] | 0 | 2 | 0 | ||
| Iron, dissolved [as Fe] | 0 | 2 | 0 | ||
| Lead, total [as Pb] | 0 | 2 | 0 | ||
| Manganese, total [as Mn] | 0 | 2 | 0 | ||
| Nickel, total [as Ni] | 0 | 2 | 0 | ||
| Silver, total [as Ag] | 0 | 2 | 0 | ||
| Zinc, total [as Zn] | 0 | 2 | 0 | ||
| Phenolics, total recoverable | 0 | 2 | 0 | ||
| Chlorine, total residual | 2 | 1 | 0 | ||
| BOD, 5-day, 20 deg. C | 1 | 1 | 0 | ||
| Phosphorus, total [as P] | 1 | 1 | 0 | ||
| Cyanide, weak acid, dissociable | 0 | 1 | 0 | ||
| Cyanide, free [amenable to chlorination] | 0 | 1 | 0 | ||
| Selenium, total [as Se] | 0 | 1 | 0 | ||
| Selenium, dry weight | 3 | 0 | 0 | ||
| Copper, dry weight | 3 | 0 | 0 | ||
| Cadmium, dry weight | 3 | 0 | 0 | ||
| Zinc, sludge, total, dry weight [as Zn] | 3 | 0 | 0 | ||
| Nickel, sludge, total, dry weight [as Ni] | 3 | 0 | 0 | ||
| Mercury, sludge, total, dry weight [as Hg] | 3 | 0 | 0 | ||
| Molybdenum, sludge, total, dry weight [as Mo] | 2 | 0 | 0 | ||
| Ann. amt sludge disposed by other method | 1 | 0 | 0 | ||
| Annual amt of sludge incinerated | 1 | 0 | 0 | ||
| Annual sludge production, total | 1 | 0 | 0 | ||
| Annual amount of sludge land applied | 1 | 0 | 0 | ||
| Annual amt. sludge disposed surface unit | 1 | 0 | 0 | ||
| Annual amt sludge disposed in landfill | 1 | 0 | 0 | ||
| Annual amt sludge transported interstate | 1 | 0 | 0 | ||
| Pollutant table from 503.13 | 1 | 0 | 0 | ||
| Level of pathogen requirements achieved | 1 | 0 | 0 | ||
| Description of pathogen option used | 1 | 0 | 0 | ||
| Vector attraction reduction alternative used | 1 | 0 | 0 |
Cited to the EPA ICIS-NPDES limits and effluent violations files (ECHO download); up to 60 rows shown, most exceedances first.
Inspections, violations and enforcement
- 15Single-event violations
| Date | What EPA recorded | Agency |
|---|---|---|
| August 10, 2026 | Dry-weather SSO, no discharge to waters of the U.S., that may endanger health or the environment | ST6 |
| July 31, 2026 | Dry-weather SSO, no discharge to waters of the U.S., that may endanger health or the environment | ST6 |
| March 15, 2026 | Dry-weather SSO, no discharge to waters of the U.S., that may endanger health or the environment | ST6 |
| February 23, 2026 | Dry-weather SSO, no discharge to waters of the U.S., that may endanger health or the environment | ST6 |
| January 6, 2026 | Dry-weather SSO discharge to waters of the U.S. that may endanger health or the environment | ST6 |
| October 31, 2025 | Dry-weather SSO discharge to waters of the U.S. that may endanger health or the environment | ST6 |
| October 27, 2025 | Dry-weather SSO discharge to waters of the U.S., not permit compliant, no endangerment | ST6 |
| October 22, 2025 | Dry-weather SSO discharge to waters of the U.S. that may endanger health or the environment | ST6 |
| September 6, 2025 | Dry-weather SSO, no discharge to waters of the U.S., that may endanger health or the environment | ST6 |
| September 2, 2025 | Dry-weather SSO discharge to waters of the U.S. that may endanger health or the environment | ST6 |
| August 18, 2025 | Dry-weather SSO discharge to waters of the U.S. that may endanger health or the environment | ST6 |
| July 29, 2025 | Dry-weather SSO discharge to waters of the U.S. that may endanger health or the environment | ST6 |
| April 6, 2025 | Wet-weather SSO discharge to waters of the U.S. that may endanger health or the environment | ST6 |
| March 14, 2025 | Dry-weather SSO discharge to waters of the U.S. that may endanger health or the environment | ST6 |
| November 4, 2024 | Wet-weather SSO discharge to waters of the U.S. that may endanger health or the environment | ST6 |
Velarion’s copy of EPA’s ICIS-NPDES files does not include the inspections, formal enforcement actions and informal enforcement actions files, so this page shows none of them. EPA’s free Detailed Facility Report on ECHO lists this permit’s inspections, enforcement actions and penalties.
Cited to the EPA ICIS-NPDES violation, inspection and enforcement files (ECHO download); up to 50 rows of each shown, newest first.
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Figures from EPA’s ICIS-NPDES download, loaded September 14, 2026.